OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at https://www.osha.gov.

September 4, 1985

Mr. Thomas S. Allen
Product Label Specialist
Ethyl Corporation
Post Office Box 14799
Baton Rouge, Louisiana 70898

Dear Tom:

Thank you for your letter of June 13, 1985, regarding questions you have concerning interpretations of the Hazard Communication Standard. The responses are as follows.

In your first question, you asked whether a material safety data sheet (MSDS) and/or label for your antiknock compound should reflect the chronic hazards of EDB or EDC when the acute hazard of tetraethyl lead is so severe. The MSDS for a compound must reflect all valid evidence concerning both the acute and chronic hazards of the constituents. Your company is free to make whatever statements seem appropriate regarding the relative hazards based upon the composition, but the evidence must be reported. That is the essence of a "right-to-know" standard.

On the label, the standard required "appropriate hazard warnings." There is obviously a need for professional judgment to determine what is "appropriate" in each situation. However, in areas where a judgment must be made, it would be prudent to err on the side of disclosure. This approach is consistent with the intent of the standard. Given the high percentage of both EDB and EDC present in your compound, my personal opinion is that the chronic hazards should certainly be on the label as well as on the MSDS.

With regard to question no. 2, I think it would be reasonable to assume that if a component that is corrosive by itself is not shown to be so when tested in a mixture where it comprises 25% of the compound, it would also not render the mixture corrosive when it comprises 1-5%. Of course, that assumption is also based upon the diluent being the same, and not something which could produce a synergistic effect. When you state that the label would only cover the acute hazards of the mixture, I assume that you mean there are no chronic hazards associated with the mixture. I am also assuming that corrosivity is the only health hazard ZDDP contributes to the mixture.

The answer to question no. 3 is related to no. 1. Again, the MSDS is a compilation of everything known about a chemical, whereas some degree of judgment is required to determine what is "appropriate" to put on a label. Certainly, the IARC information must be on the MSDS. And unless there is a scientifically defensible reason not to, I would indicate the cancer hazard on the label as well.

I hope this information is helpful to you. If we can be of further assistance to you, please do not hesitate to contact us.


Jennifer C. Silk
Health Scientist
Health Standards Programs




JUNE 13, 1985





Miss Jennifer Silk
U.S. Department of Labor - OSHA
Room N3663
200 Constitution Avenue, N.W.
Washington, DC 20210

Dear Jennifer:

I very much appreciate your willingness to answer in writing several questions that were causing us concern in the MSDS and label areas.

Question No. 1

For our antiknock compound with the composition

    Tetraethyl lead          61.45%
    EDB                      17.85%
    EDC                      18.80%
    Inerts & Dye              1.90%

We currently classify the product as highly toxic by ingestion, absorption, and inhalation.

In developing new labels and MSDS to comply with current OSHA Hazard Communication Rule we wonder if we should show on the MSDS and/or label the chronic hazards associated with the EDB and EDC?

In our judgment the PEL of TEL at 75 ug/m3 coupled with the industrial hygiene required to avoid toxicity from TEL will result in no meaningful risk from either EDB or EDC. In addition to respiratory protection where overexposure might occur, protective clothing, foot protection, goggles and impermeable gloves are required.

Because of the wide PEL difference between TEL at 0.075 mg Pb/m3 we are concerned that emphasizing the chronic hazard from EDB will detract from the emphasis needed to protect from the organic lead hazard.

Question No. 2

For some our lube oil additives containing ZDDP (Zinc Dialkyldithiophosphate) we would like to know if our toxicologist can use judgment for those mixtures containing substantially less ZDDP than a tested mixture? Specifically, we have found that oil mixtures containing less than 25 wt % of ZDDP are not corrosive. We feel that mixtures containing 5% or 1% could be considered not corrosive on a judgment without test.

In these cases the MSDS would list the ZDDP as being present but it would not state that the ZDDP was itself corrosive or that the mixture was corrosive.

The label would of course cover only the acute hazards of the mixture.

Question No. 3

Many of our products contain from 1 to 15% of an aromatic oil listed in IARC as an animal carcinogen. The exact amount is confidential. We would of course show this aromatic oil as present. We would, however, use the judgment of the toxicologist in determining when to list the chronic hazard on the label. We would do this depending on the amount of diluent oil we judge to be a cancer hazard. Is this policy in accord with the interest of the OSHA rule?

As I explained to you on the phone, all of us within Ethyl Corporation are enthusiastic in complying with all facets of the OSHA rule. It was in fact this enthusiasm that caused honest differences of opinion within the group and lead to this inquire. These few answers will greatly aid us in fulfilling our corporate obligations in this area.

We very much appreciate your helping us on this matter.


Thomas S. Allen
Product Label Specialist
Toxicology and Industrial Hygiene Department
P.O. Box 14799
Baton Rouge, Louisiana 70898
Telephone (504)389-7600